THE QUESTIONABLE UNITY OF THE CONCRETE OPERATIONS STAGE

This study was designed to investigate the reported capacity of some non-conservers of weight to deal successfully with tasks involving multiple classification. Tests of seriation, class inclusion, conservation of quantity, weight and volume, and eight multiple classification tasks (after Inhelder and Piaget) were given to 49 recently immigrated Yugoslav children (median age 10.5 years) in Australian primary schools, using Serbo-Croat as the language of administration. Performance on most of these tests of concrete operational behaviour was found to be about two years retarded as compared with Genevan data. On seven of the eight multiple classification tasks, not less than one-third of non-conservers of weight were able to give operational solutions. No differences were found in this group of 22 non-conservers, in terms of success vs. non-success in multiple classification, in age, sex, urban/rural domicile of origin, more/less recent arrival in Australia, or Macedonian/Serbian ethnicity. It is concluded that a case can be made for not regarding the concrete operations stage as a formal unity, but instead (following Flavell and Wohlwill) as a set of structures without necessary interdependence.     

A comparison of two measures of egocentrism

This study examined the relationship between two prominent measures of egocentrism, Enright's Adolescent Egocentrism Scale (AES) and Elkind's Imaginary Audience Scale (IAS), in a sample of 458 adolescents, between 10 and 15 years old. Both correlational and factor analyses indicated that the two measures assess distinctly different phenomena. As predicted, IAS scores were correlated with self-reported levels of shyness, nervousness, and social skills. These results provide partial evidence for the validity of the IAS as a measure of self-consciousness, though not necessarily egocentrism per se. The validity of the AES was not examined.     

Formal operations, the imaginary audience and the personal fable

One hundred twenty-nine 6th, 8th, 10th/11th, and 12th graders were administered Enright, Lapsley, and Shukla's Adolescent Egocentrism Scale (AES) and How Is Your Logic?, a Piagetian-based, group-administered, written test of cognitive development. A series of ANOVAs on four scales of the AES (imaginary audience, personal fable, self-in-general, nonsocial) provided partial support for Inhelder and Piaget's, and Elkind's views that adolescent egocentrism is a function of beginning formal operations. Discussion focused on the difficulty of assessing the true thoughts/feelings of persons who are worried how they will appear to others.     

Non-verbal and verbal judgements of length invariance by young children.

One hundred and fifty non-conservers in length were assessed for their ability to make a non-verbal judgement of length invariance on a task employing a train-transfer design in which the stimuli were pairs of pencils. Seventy per cent of the children from the group who had to respond to length equality as opposed to inequality made the correct invariance judgement and could, moreover, characterize their choices in invariance language (e.g. 'same size') whilst still failing the standard verbal task in which such phrases were used by the experimenter. This is regarded as supporting the hypothesis that the non-conserver's linguistic difficulty is not with framing the verbal judgement but in interpreting a question which he believes has to be interpreted unidimensionally in such a context of perceptual change.     

The social reality of the imaginary audience: a grounded theory approach

Traditional approaches to understanding the imaginary audience are challenged in this study. Three hundred sixty-one British schoolchildren (aged 14 and 15 years) were asked to express their worries and concerns, using grounded theory methodology. Qualitative responses were collated and coded according to emerging categories, with "what other people think" identified as the central concern. In particular, the findings are used to critique Elkind's (1967) theory of adolescent egocentrism. Data presented in this study suggest that adolescents worry about what other people think because there are real personal and social consequences. Such concerns are seen as being based in social reality and are not imaginary as Elkind suggested. In conclusion, new methodologies which place young people at the center of the analysis are advocated.     

Attention and cognition

Forty 4-year-old children were subjects in an experimental designed to determine whether learning to attend to relevant cues is a sufficient condition for acquisition of length and number conservation. Three groups of non-conservers were trained by means of an oddity-problem procedure to attend to the cues specifying either length, number, or both length and number. They were subsequently tested along with an untrained control group on tasks of length, number, mass and continuous quantity conservation. Some improvement in conservation was found, but it was neither impressive in magnitude nor specific to the cues of training. For example, the group trained to attend to length cues conserved length about 25% of the time, the same rate at which this group also conserved number, mass, and liquid quantity. This non-specificity is contrary to an attention hypothesis and suggests instead that training, to the extent it was effective, induced a general, abstract quantitative knowledge.     

Social desirability in the bedroom: Role of approval motivation in sexual relationships

One-hundred and twelve unmarried participants completed a questionnaire that examined the relationship between gender and approval motivation (assessed by the Marlowe—Crowne Social Desirability Scale) and college students' stereotypes of and experiences with power in sexual encounters. Regardless of approval motivation, students described men as using power predominantly to have sex and women as using power predominantly to avoid having sex. However, interactions between need for approval and gender suggested that high-need-approval women might be having more experiences with sex and power in the bedroom than high-need-approval men. These results are discussed in light of Elkind's hypothesis that adolescent behavior conforms to an imaginary audience of peers and the Crowne-Marlowe model of approval motivation.An earlier version of this article was presented in the symposium Gender and Power Strategies: Contrasting Models and Applications, at the meeting of the American Psychological Association, Los Angeles, August 24–28, 1981. The authors wish to express appreciation to J. W. McCormick for his assistance with data analysis and to E. Allgeier for her helpful comments on a previous draft.     

Perceptual cues used in reproduction of inspired volume

Man is capable of reproducing an inspired lung volume (IV) with relative precision (±3 %–8 %). To investigate the importance of cues which may be used to determine IV, we performed two experiments. In each, the subject inspired a “standard” breath (from resting end~xpired lung volume) corresponding to 25%, 50%, or 75% of inspiratory capacity (IC) and then expired nearly completely. From this expired volume, the subject either tried to reproduce the tidal volume (i.e., volume of air inspired) of the first breath (volume reproduction) or to reproduce the previous end-inspired lung volume (position reproduction). The constant error indicated that subjects overestimated tidal volume by about 200 ml. Despite this overestimation, the variability of reproduction was less for volume reproduction than for position reproduction when IV was small. The JND for volume reproduction increased linearly with increasing IV, whereas the JND for position reproduction was similar at all IVs so that the Weber ratio decreased. These observations suggest that, in the perception of inspired volume, the sensation of end-inspired position is important when the inspired volume is large, but that subjects apparently rely on some other cue to reproduce small lung volumes accurately.     

Perceptual independence of size and weight by dynamic touch

Historically, the existence of a size-weight illusion has led to the conclusion that perceptions of size and weight are not independent. A dependence of perceived heaviness on physical volume (perceptual separability), however, is different from a dependence on perceived volume (perceptual independence). Three experiments were conducted to evaluate perceptual independence. The relations between perceived size and weight and physical size and mass were evaluated in Experiment 1. Perceived weight, length, and width were structured only by the corresponding physical variables, whereas variations in volume were not separable from variations in mass. F. G. Ashby and J. T. Townsend's (1986) test for perceptual independence was applied in Experiment 2. Perceived weight was independent of perceived length and volume. Experiment 3 used a magnitude estimation paradigm to investigate the extent to which information-perception relations could be related to the observed patterns of separability and independence.     

Normalized pulse volume and blood volume as separate indices of finger arterial and venous vascular tone: Examination under propofol

Abstract: This study examined the newly proposed indices for estimating finger vascular tone, which can be obtained from near infrared transmittance photoplethysmographic recordings; normalized pulse volume (NPV) and blood volume (BV). They were recorded for seven male and two female students under continuous infusion of and recovery from propofol. Concomitant hemodynamic measurements were made with a non-invasive impedance cardiograph and a continuous blood pressure monitor. Normalized pulse volume showed no apparent dose-dependency and was negatively correlated with total peripheral resistance. In contrast, BV increased dose-dependently with propofol concentration and was negatively correlated with cardiac preload index (PLI) and with stroke volume (SV) at higher concentrations. The supplementary structural equation modeling procedure effectively illustrated causal relationships between BV, PLI and SV. In conclusion, the present data suggest that NPV and BV independently reflect arterial and venous tone in the finger tip, respectively. Although the underlying mechanisms remain unclear, BV is more sensitive to vascular dilation under propofol anesthesia.     

MRI-Assessed Volume of Cerebellum Correlates with Associative Learning

Richard F. Thompson's cerebellar model of classical eyeblink conditioning highlights Purkinje cells in cerebellar cortex and principal cells in the deep cerebellar nucleus as the integrating cells for acquisition of conditioned responses (CRs). CR acquisition is significantly slower in rabbits with lesions to cerebellar cortex and in Purkinje cell-deficient mice that lose all cerebellar cortical Purkinje cells. Purkinje cells are the largest neurons in the cerebellum and contribute significantly to cerebellar volume. Magnetic resonance imaging (MRI) was used to assess cerebellar volume in humans. Cerebellar volume was related to eyeblink conditioning (400-ms delay procedure) in 8 adults (21-35 years) and compared to 8 older adults (77-95 years) tested previously (Woodruff-Pak, Goldenberg, Downey-Lamb, Boyko, & Lemieux, 2000). In the young adult sample, there was a high correlation between percentage of CRs in a session and cerebellar volume (corrected for total intracranial volume [TIV], r =.58, p =.066). There were statistically significant age differences in cerebellar volume, t(14) = 8.96, p <.001, and percentage of CRs, t(14) = 3.85, p <.002, but no age difference in TIV. Combining the young and older adult sample, the correlation between percentage of CRs and cerebellar volume (corrected for TIV) was.832 (p <.001). Cerebellar volume showed age-related deficits likely due to Purkinje cell loss. Individual differences in classical eyeblink conditioning are associated with differences in cerebellar volume, supporting Thompson's model of a cerebellar cortical role in facilitating this form of associative learning.     

Uncoupled leftward asymmetries for planum morphology and functional language processing

Explanations for left hemisphere language laterality have often focused on hemispheric structural asymmetry of the planum temporale. We examined the association between an index of language laterality and brain morphology in 99 normal adults whose degree of laterality was established using a functional MRI single-word comprehension task. The index of language laterality was derived from the difference in volume of activation between the left and right hemispheres. Planum temporale and brain volume measures were made using structural MRI scans, blind to the functional data. Although both planum temporale asymmetry (t(1,99) = 6.86, p < .001) and language laterality (t(1,99) = 15.26, p < .001) were significantly left hemisphere biased, there was not a significant association between these variables (r(99) = .01,ns). Brain volume, a control variable for the planum temporale analyses, was related to language laterality in a multiple regression (beta = -.30, t = -2.25, p < .05). Individuals with small brains were more likely to demonstrate strong left hemisphere language laterality. These results suggest that language laterality is a multidimensional construct with complex neurological origins.     

Oral perception of bolus in healthy young women

This study was designed to characterize oral perception of both weight and volume of boluses. A total of 80 healthy young female subjects was recruited and divided into bolus weight (n = 40) and bolus volume (n = 40) conditions. Tap water (25 degrees C) was the experimental material, and seven reference stimulus amounts ranging from 10 to 40 (grams and mL) were prepared. The reference stimuli, including a modulus of 20 (grams and mL), were delivered to the subjects in randomized order. The estimated magnitudes (psi) conformed to both the Fechner's and Stevens' psychophysical laws by the following equations: (1) psi(W) = 314.3 log (S+1) - 300.2 where S is stimulus intensity or weight, and psi(V) = 249.7 log (S+1) - 222.3 (volume) on logarithmic (log)-linear scales, and (2) psi(W) = 1.908 S1.297 and psi(V) = 4.097 S1.032 on log-log scales, respectively. The results indicate that oral perception of bolus weight and bolus volume conforms to the representative psychophysical laws.     

老年人整体运动敏感性降低的脑灰质体积变化基础

本研究使用多体素模式分析方法和随机点阵范式,首次探索了老年人整体运动敏感性（GMS）下降和其脑灰质体积下降间的关系。结果发现,老年人GMS显著低于年轻人,老年人V5/MT、V3和额顶等脑区灰质体积显著小于年轻人;V5/MT和V3区的灰质体积信号可以有效预测个体的GMS。结果提示,V5/MT区和V3区,特别是V3区的灰质体积下降可能是老年人GMS下降的主要原因;而基于“去分化假设”,全脑范围内其余脑区的灰质体积下降可能也在一定程度上与老年人GMS下降有关。     

Relations among heavy training stress,mood state,and performance for male junior rowers

This study investigated the influence of rapidly increased training volume on performance and recovery-stress state perceived by 10 male junior rowers. The training during the 6-day period amounted to 21.5 +/- 2.2 hr., which was equivalent to an average increase in training load by approximately 100% compared to their average training volume during the previous 4 wk. The time to row 2,000 m on a rowing ergometer and resting cortisol level were significantly increased after the 6-day training period. Scores on subscales of the Recovery Stress Questionnaire for Athletes significantly increased for somatic component of stress (Fatigue) and decreased factor indicating recovery (Social Relaxation) after the heavy training period. A correlation of .63 was found between increased training volume and scores on the Conflicts/Pressure subscale at the end of the heavy training period. Correlations were also found between changes in training volume with changes on subscales of Sleep Quality (r=-.64) and Burnout/Personal Accomplishment (r=-.66). Changes in resting cortisol levels as a result of heavy training stress were related to the changes in the following stress subscales: Social Stress (r=.76), Fatigue (r=.64), Disturbed Breaks (r=.65), and Fitness/Injury (r=.67). Changes in performance, perceived recovery-stress state and resting plasma cortisol level reflect increased stress due to high training. These results suggest that the Recovery Stress Questionnaire for Athletes could be used to evaluate the effects of rapidly increased training volume for male junior rowers.     

Discriminating the volume of motion-defined solids

We investigated the ability of human observers to discriminate an important global 3-D structural property, namely volume, of motion-defined objects. We used convex transparent wire-frame objects consisting of about 12 planar triangular facets. Two objects, vertically separated by 7°, were shown simultaneously on a computer display. Both revolved at 67°/sec around a common vertical axis through their centers of mass. Observers watched the objects monocularly for an average of three full rotations before they responded. We measured volume discrimination as a function of absolute volume (3–48 cm³; 1 m viewing distance) and shape (cubes, rods, and slabs of different regularity). We found that (1) volume discrimination performance can be described by Weber’s law, (2) Weber fractions depend strongly on the particular combination of shapes used (regular shapes, especially cubes, are easiest to compare, and similar shapes are easier to compare than different shapes), and (3) humans use a representation of volume that is more veridical and stable in the sense of repeatability than a strategy based on the average visible (2-D) area would yield.     

THE COSTS OF EATING: A BEHAVIORAL ECONOMIC ANALYSIS OF FOOD REFUSAL

Behavioral economic concepts were applied to the analysis and treatment of pediatric feeding disorders in a clinical setting. In Experiment 1, children who chronically refused food were presented with varying amounts of food on a spoon (empty, dipped, quarter, half, and level). Each child exhibited a different but orderly demand function of response (acceptance, expulsion, and mouth clean) by cost (increasing spoon volume) for a constant pay-off of toys and social interaction. In Experiment 2, physical guidance or nonremoval of the spoon for food refusal was initiated at the smallest spoon volume with low levels of acceptance, and was subsequently introduced at the largest spoon volume with moderate levels of acceptance. Treatment was effective in increasing acceptance, and these effects generalized hierarchically across untargeted spoon volumes. The results of both studies provide preliminary support that increasing spoon volume can be equated conceptually with increasing response effort, and that the change from differential reinforcement to physical guidance or nonremoval of the spoon appears to have altered the elasticity of each child's demand function.     

Content variations and performance on formal operational tasks by gender,social class and ability1

The role of task content, gender, social class and cognitive ability in performance on two formal operational tasks is explored in this paper. The participants were 110 Icelandic 12-year-olds, early and late developers, males and females from all socio-economic groups. Two tasks of variable isolation (the pendulum and three content versions of the “plant” problem) and two measures of volume conservation (three traditional tasks and three tasks formally identical whose content was pictorial social play) were presented individually in a school setting. The results suggest that content variations have differential consequences for the performance of early and late developers at age 12. Both the nature of logical competence and task content affect solutions, as suggested by Overton and collaborators in 1987. Some social class and gender differences were observed on two Piagetian tasks (pendulum and volume), which was reduced by changing the task content in the case of social class but not in that of gender. As the gender difference in volume conservation was not reflected ins chool achievement nor on other cognitive tasks it was interpreted as a gender bias. The findings are discussed in view of recent literature on the development of cognitive theory with increased emphasis on context and meaning in a post-structural intellectual climate.     

Psychophysical scales of apparent heaviness and the size-weight illusion

The apparent heaviness of a set of 40 cylindrical objects was scaled by the method of magnitude estimation. The objects varied in weight, volume. and density. There were three main conclusions: (1) For any constant volume, heaviness grows as a power function of weight; the larger the volume. the larger the exponent of the power function. The family of such power functions converge at a common point in the vicinity of the heaviest weight that can be lifted. (2) For any constant density (i:e., weight proportional to volume), heaviness does not grow as a power function of weight. (3) For any constant weight, heaviness decreases approximately as a logarithmic function of volume; the constants of the log function depend systematically on the weight of the object. The outcome furnishes a broad quantitative picture of apparent heaviness and of the size-weight illusion (Charpentier’s illusion).     

Discrimination thresholds for haptic perception of volume, surface area, and weight

The present study investigated the human ability to discriminate the size of 3-D objects by touch. Experiment 1 measured the just noticeable differences (JNDs) for three tasks: (1) discrimination of volume without availability of weight information, (2) discrimination of volume with weight information available, and (3) discrimination of surface area. Stimuli consisted of spheres, cubes, and tetrahedrons. For all shapes, two reference sizes were used (3.5 and 12 cm(3)). No significant effect of task on the discriminability of objects was found, but the effects of shape and size were significant, as well as the interaction between these two factors. Post hoc analysis revealed that for the small reference, the Weber fractions for the tetrahedron were significantly larger than the fractions for the cube and the sphere. In Experiment 2, the JNDs for haptic perception of weight were measured for the same objects as those used in Experiment 1. The shape of objects had no significant effect on the Weber fractions for weight, but the Weber fractions for the small stimuli were larger than the fractions for the large stimuli. Surprisingly, a comparison between the two experiments showed that the Weber fractions for weight were significantly larger than the fractions for volume with availability of weight information. Taken together, the results reveal that volume and weight information are not effectively combined in discrimination tasks. This study provides detailed insight into the accuracy of the haptic system in discriminating objects' size. This substantial set of data satisfies the need for more fundamental knowledge on haptic size perception, necessary for a greater understanding of the perception of related properties, as well as of more general perceptual processes.